I would love to have more minimalist options like the Corsa B in the States, but evidently the manufacturers are convinced we "don't want them." Well, some of us do.
I see the Corsa's rear end and how it rounds over gently at the rear corners. Wiser people than I have pointed out that cleaner flow separation is better for aero, and that rear corner would be better if it were sharper.
Orange4boy's
Previa suffered a similar design flaw and he improved on it with added-on trailing edges to continue the vehicle's rearward taper while providing sharp cutoffs. If I recall correctly when he did it the first time he used stainless steel, which made my jaw drop.
Anyway, when you only have 54hp to play with, giving them less to do is a good thing, and as mods go it's small enough to maybe slip under draconian European regulations.